textproduct: Quad Cities

KEY MESSAGES

- Extreme Heat Warning continues through Thursday evening for much of the area with ongoing prolonged period of hot and very humid conditions. Daily peak heat index values of 100 to 105 and nighttime low temperatures only dropping into the mid to upper 70s.

- Humid conditions will continue into the holiday weekend. Cloud cover and slowly increasing storm chances will help to lower ambient temperatures. Storm chances will increase from the west and north into the weekend. Some storms may be strong to severe as well as have the potential to produce locally heavy rainfall.

SHORT TERM /THROUGH TONIGHT/

Issued at 240 AM CDT Wed Jul 1 2026

No adjustments made to the ongoing heat headlines for now. Stout upper ridge and EML centered from the lower MS RVR Valley to the central Atlantic is keeping the "ring of fire" pattern close by from the deep southwest plains, the MO RVR Valley and ringing around the northern half of the GRT LKS. Main fcst concern for the day is if any convection can bleed into the CWA from the west or north, or develop in our area. Looking at the thermal profiles and lingering ridge placement, it's more likley most of the CWA will stay dry through 12z Thu as opposed to having storms blowing through it. But there is another nice nocturnal LLVL convergence swath happening again tonight acrs the eastern SD/NE border region and extending just south of the IA/MN border into southern WI. There is a chance that some of this activity may make it down into the northern CWA along the Hwy 20 corridor or even pushing Hwy 30 if they manage some cool pool assistance. Will have to account for this potential with at least some low to moderate CHC POPs (30-50%) in the north mainly after midnight and into Thu morning before they start to decay diurnally. If some mature storms can make it into the north, damaging winds would be the primary threat as well as locally heavy rain.

As for temps today, little in the way of airmass change and expect similar highs as yesterday with a lot of lower 90s and a few spots approaching the mid 90s. Wednesday night lows should remain rather high, only dipping to the middle to upper 70s, which should offer little relief from the ongoing heat.

LONG TERM /THURSDAY THROUGH TUESDAY/

Issued at 240 AM CDT Wed Jul 1 2026

Thursday...This is the period and into Friday where the model ensembles suggest wave and jet energy continue to suppress the amplitude of the southeast ridge and allow the flattening and southeastward adjustment of the main storm track acrs the central plains into the GRT LKS. May have to account for some lingering storms or cloud debris in the north Thu morning, while farther south things heat up again, warranting the Extreme Heat Warning extension in those areas through Thu evening. With the southeastward adjustment of the mass fields, will have to watch the new convergence zone shifting more acrs central IA for convective initiation Thu afternoon and evening with any short wave or MCV arrival in the flow aloft. Even with marginal looking shear profiles currently that far out, there should be very high MUCAPE fields of 3-4 kJ/kg to fuel strong convection. Will have to watch for an isolated storm in the afternoon mainly in the west, with better chances locally coming mid Thu evening and into the overnight period as upstream convective development acrs central IA propagates eastward potentially as an MCS. Damaging winds, heavy rainfall, and possibly some hail would be the main concerns Thursday and Thursday night.

Friday through Tuesday...Boundaries and cloud cover left over from the Thursday night storms will help to hold down temperatures and also provide boundaries for diurnal convection Friday afternoon that will continue into Friday night.

Starting Friday, rain chances will increase to 30-50% but not all areas will see rain.

Saturday through Tuesday Assessment...a certainty (>95%) that humid conditions will continue. Low (20-30%) confidence on storm timing and areal coverage.

Another disturbance moving through the Midwest Saturday and Saturday night currently looks to have the better chances to produce rain. This may or may not be in the form of an organized storm complex. Right now, the model consensus has rain chances at 30-55% with the better chances along/north of I-80.

Starting Sunday, there are additional upper level disturbances/waves progged to move through the area each day. However, there are timing differences. The main message is that while there are rain chances for each day, not everyone will see rain. Additionally, areal coverage of any precip is low at 15 to 25 percent.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 621 AM CDT Wed Jul 1 2026

VFR conditions are expected through most of, if not the entire, TAF period. Any lingering low-level wind shear this morning will taper off as the boundary layer mixes, leading to another day of breezy south-southwest winds. Gusts between 20-25 knots are expected. Near the end of the TAF period, there is a low to medium chance (20-40%) of thunderstorms late tonight into early Thursday morning for areas along and north of Highway 30, but high-resolution models show noteworthy differences for the timing and coverage so uncertainty exists. If any of our TAF terminals were to be impacted by storms tonight, it would be near CID and DBQ.

DVN WATCHES/WARNINGS/ADVISORIES

IA...Extreme Heat Warning until 10 PM CDT this evening for IAZ040>042-051>054. Extreme Heat Warning until 10 PM CDT Thursday for IAZ063>068- 076>078-087>089-098-099. IL...Extreme Heat Warning until 10 PM CDT this evening for ILZ001- 002-007. Extreme Heat Warning until 10 PM CDT Thursday for ILZ009- 015>018-024>026-034-035. MO...Extreme Heat Warning until 10 PM CDT Thursday for MOZ009-010.